Wildland fires

As many as 90 percent of wildland fires in the United States are caused by people, according to the U.S. Department of Interior. Some human-caused fires result from campfires left unattended, the burning of debris, negligently discarded cigarettes and intentional acts of arson. The remaining 10 percent are started by lightning or lava.

According to Verisk’s 2017 Wildfire Risk Analysis 4.5 million U.S. homes were identified at high or extreme risk of wildfire, with more than 2 million in California alone. Losses from wildfires added up to $5.1 billion over the past 10 years.

Wildfires by year

2018: From January 1 to August 6, 2018, there were 38,832 wildfires, compared to 40,007 wildfires in the same period in 2017, according to the National Interagency Fire Center. About 5.1 million acres were burned in the 2018 period, compared with 5.9 million in 2017.

The Mendocino Complex fire broke out on July 27th in Northern California and grew to be the largest fire in state history with over 283,000 acres burned.

The Carr fire, which broke out on July 23 in Northern California, is the 6thmost destructive fire in the state’s history and is still not contained as of August 6. Six fatalities are attributed to the fire and over a thousand structures have been destroyed.

2017: In 2017, there were 71,499 wildfires, compared to 65,575 wildfires in the same period in 2016, according to the National Interagency Fire Center. About 10 million acres were burned in the 2017 period, compared with 5.4 million in 2016. 2017 acres burned were higher than the 10-year average.

Beginning October 6 and continuing until October 25, eight counties in Northern California were hit by a devastating outbreak of wildfires which led to at least 23 fatalities, burned 245,000 acres and destroyed over 8,700 structures.

In December five major fires in Southern California destroyed over a thousand homes and buildings. One of the fires, the Thomas Fire, became the largest wildfire ever recorded in California. Catastrophe modeling firm RMS estimates that the Thomas Fire will cost up to $2.5 billion in insured losses. The California Department of Insurance reported that insurance claims from the October-December fires add up to almost $12 billion, which makes the 2017 fire season the costliest on record.

2016: There were a total of 5.5 million acres burned by wildfires in 2016. On May 1 of that year, a wildfire broke out in the Alberta city of Fort McMurray. The fire was the costliest ever Canadian natural disaster for insurers, with 1,600 buildings destroyed and more under threat. Two fatalities are attributed to the fire and the entire population of about 90,000 were evacuated. The smoke from the fire could be seen as far south as Iowa.

(1) Property coverage only for catastrophic fires. Effective January 1, 1997, ISO's Property Claim Services (PCS) unit defines catastrophes as events that cause more than $25 million in insured property damage and that affect a significant number of insureds and insurers. From 1982 to 1996, PCS used a $5 million threshold in defining catastrophes. Before 1982, PCS used a $1 million threshold. Does not include wildfires in 2017. (2) Adjusted for inflation through 2016 by ISO using the GDP implicit price deflator.

Source: The Property Claim Services® (PCS®) unit of ISO®, a Verisk Analytics® company